Patents Assigned to Quadracast Systems, Inc.
  • AM Broadcast tuner with automatic gain control
    Patent number: 4227256
    Abstract: An RF amplifier stage of an AM broadcast tuner is disclosed wherein, depending upon the power level of the received input signal, said input signal is amplified by a high gain radio frequency amplifier, or by a low gain radio frequency amplifier, or by a combination of both the high and low gain radio frequency amplifiers at intermediate levels. This system provides wide dynamic range and low distortion in that it prevents amplifier saturation and reduces intermodulation product signal levels.
    Type: Grant
    Filed: January 6, 1978
    Date of Patent: October 7, 1980
    Assignee: Quadracast Systems, Inc.
    Inventor: Gerald T. O'Keefe
  • AM/FM Intermediate frequency gain stage
    Patent number: 4150336
    Abstract: This invention discloses a versatile gain circuit for use as a combination AM and FM intermediate frequency amplifier. The uniqueness of the circuit is large FM gain and large AM dynamic range.
    Type: Grant
    Filed: January 6, 1978
    Date of Patent: April 17, 1979
    Assignee: Quadracast Systems, Inc.
    Inventor: Gerald T. O'Keefe
  • Automatic control for phonographs playing records of different speeds
    Patent number: 4062547
    Abstract: An automatic means is provided for setting a phonograph record player to the proper speed, depending on the type of record placed thereon. A magnet detection circuit is employed in the player and a magnetic adapter is employed for 45 RPM records.
    Type: Grant
    Filed: August 13, 1976
    Date of Patent: December 13, 1977
    Assignee: Quadracast Systems, Inc.
    Inventor: Louis Dorren
  • Quadrature multiplying four-channel demodulator
    Patent number: 4061882
    Abstract: A decoder is provided for a FM radio four-channel system having the usual 19 kHz pilot signal, a first subcarrier at 38 kHz, a second subcarrier in quadrature therewith, and another subcarrier at 76 kHz. The decoder of the present invention is a time division system wherein the 19 kHz pilot signal is doubled and the phase shifted 90.degree.. This produces sine and cosine 38 kHz signals to provide a first pair of outputs, and each of these signals is inverted to provide a second pair of outputs. By properly adding the four outputs thus derived, switching signals are provided to decode the four channel information.
    Type: Grant
    Filed: August 13, 1976
    Date of Patent: December 6, 1977
    Assignee: Quadracast Systems, Inc.
    Inventor: Louis Dorren
  • Multi-mono FM system
    Patent number: 3943294
    Abstract: A multi-mono FM transmission and reception system is provided whereby during a portion of the programming a four-channel music system can be broadcast and received and during another portion of the programming four discrete languages can be broadcast and separately received. An automatic switching system is provided so that with the proper equipment, one receives a four-channel music program during a musical transmission and a single selected voice channel during voice transmissions. Provision is made so that the main language of the country will be received on a mono receiver.
    Type: Grant
    Filed: June 21, 1974
    Date of Patent: March 9, 1976
    Assignee: Quadracast Systems, Inc.
    Inventor: Louis Dorren
  • Cartridge muting circuit
    Patent number: 3937902
    Abstract: A muting circuit is provided for a phonograph record amplifier employing a semi-conductor cartridge wherein the cartridge has a shorting switch operative during the changing cycle wherein the amplifier associated with the cartridge is deactivated during the changing cycle of the pickup preventing transients in the output of the amplifier.
    Type: Grant
    Filed: April 18, 1974
    Date of Patent: February 10, 1976
    Assignee: Quadracast Systems, Inc.
    Inventor: Louis Dorren